<app-child [childrenName]="childrenName" [count]=1 (cry)="handlerCry($event)"></app-child>
<app-child [childrenName]="'张三'" [count]="cnt" (cry)="handlerCry($event)" (happy)="handlerHappy($event)"
    #ch1></app-child>
<div>username:{{this.username.length}}1212</div>
<div #divElement>this 12123is a</div>

<button (click)="print()" appMyDerirective01 class="btn btn-success"> 打印#</button>